Energy absorbing device for a steering column

Abstract

An energy absorbing device for a steering column assembly is provided. The device includes a first strap coupled to the steering column assembly, the first strap configured to absorb energy of an impact event on the steering column assembly, a second strap coupled to the steering column assembly. The second strap is also configured to absorb energy of an impact event on the steering column. A coupling device connects the second strap to the first strap such that both the first strap and the second strap absorb energy of a first impact event. The coupling device selectively uncouples the second strap from the first strap such that the only the first strap absorbs energy of a second impact event.

Having thus described the invention, it is claimed: 
     
       1. An energy absorbing device for a steering column assembly, the device comprising:
 a first strap coupled to the steering column assembly, the first strap configured to absorb energy of an impact event on the steering column assembly; 
 a second strap coupled to the steering column assembly, the second strap configured to absorb energy of an impact event on the steering column; and 
 a coupling device attaching the second strap to the first strap such that both the first strap and the second strap absorb energy of a first impact event, and the device is configured to selectively uncouple the second strap from the first strap in advance of a second impact event wherein during the first impact event the first strap is configured to be placed in tension by the coupling device and the second strap is configured to be placed in compression by the coupling device. 
 
     
     
       2. The energy absorbing device of  claim 1 , wherein the coupling device retains an end of the first strap to an end of the second strap. 
     
     
       3. An energy absorbing device for a steering column assembly, the device comprising:
 a first strap coupled to the steering column assembly, the first strap configured to absorb energy of an impact event on the steering column assembly; 
 a second strap coupled to the steering column assembly, the second strap configured to absorb energy of an impact event on the steering column; and 
 a coupling device attaching the second strap to the first strap such that both the first strap and the second strap absorb energy of a first impact event, and the device is configured to selectively uncouple the second strap from the first strap in advance of a second impact event wherein the first strap and the second strap are co-linear with the coupling device so the first strap, the second strap, and the coupling device are configured to move together during the first impact event. 
 
     
     
       4. The energy absorbing device of  claim 3 , wherein during the first impact event the first strap is configured to be placed in tension by the coupling device and the second strap is configured to be placed in compression by the coupling device. 
     
     
       5. A steering column assembly comprising:
 a mounting bracket; 
 a first jacket coupled to the mounting bracket and having a first longitudinal axis; 
 a second jacket slidably disposed with the first jacket for telescoping movement along the longitudinal axis relative to the first jacket; and 
 an energy absorbing device operatively associated with the second jacket, the energy absorbing device comprising: 
 a first strap coupled to the second jacket, the first strap configured to absorb energy of an impact event on the steering column assembly; 
 a second strap coupled to the second jacket, the second strap configured to absorb energy of an impact event on the steering column; and 
 a coupling device attaching the second strap to the first strap such that both the first strap and the second strap absorb energy of a first impact event, and the coupling device is configured to selectively uncouple the second strap from the first strap prior to a second impact event, and the first strap and the second strap are generally co-linear with the coupling device. 
 
     
     
       6. The energy absorbing device of  claim 5 , wherein during the first impact event the first strap is configured to be placed in tension by the coupling device and the second strap is configured to be placed in compression by the coupling device. 
     
     
       7. The energy absorbing device of  claim 5 , wherein the coupling device retains an end of the first strap to an end of the second strap.